Flash Rust In Tanks - Is It Dangerous To Breathe?

[realdiver7]

I was testing out a couple of regs today at home using a steel 100 tank, and noticed a fine coating of flash rust dust inside of my 2nd stage. The 1 year old steel tanks have had a little flash rust in them since last summer, but nothing serious and no pitting.

The last few times I've been diving with these tanks I've noticed that everything tastes strange, or lacks in taste when I eat or drink after the dives. Today I had "cotton mouth" and a slight headache, but I'm not sure if the headache came from breathing the air in the tank or not.

My question is....what kind of known health hazards are there, if any, from breathing from tanks that contain some flash rust, especially since the residue is showing up on the inside of my 2nd stage? Apparently the flash rust is now suspended in the gas mixture, instead of just remaining attached to the inside walls.

I'm sure I'll get some good common sense replies because obviously breathing anything other than what we are supposed to breathe cannot be healthy!

Thank you.

 

[ScubaSarus]

I was under the impression from a recent discussion that flash rust at a certain amount was fine to have in your tank. I was very surprised to hear that. Your linked thread does make for a legitamte concern and I will mention these issues to my LDS that does my hydros in the near future.

Thanks for posting. Ide like to know more for curiosity and safety sakes..

 

[DennisW]

In a word, Yes. A bit of flash rust in a steel tank is fairly normal. As a matter of fact that flash rust will keep the tank from oxidizing deep into the metal and causing pitting. There was an old flintlock called the Brown Betty. It was called that because it had a thin coating of rust instead of Bluing (which is a form of oxidation) to prevent more severe rusting.

 

[realdiver7]

OK thanks, I appreciate your replies. After checking several other 2nd stages tonight that I had attached to the same steel tank, I did not find any flash rust inside any of the other 2nd stages.

Maybe it was just some rare, freak occurrence, or maybe it wasn't flash rust in the 2nd stage to begin with. Could have been dust that I hadn't noticed before. Anyway, for safety's sake, I flushed all 2nd stages out tonight with fresh water and air from an aluminum tank and checked out my 1st stage. Everything appears to be OK for now.

 

[DennisW]

I apologize for missing the part about the rust in the second stage. Nothing but air should get to your second stage. There is a filter in the first stage (or there should be) that you can see. Is it there? It is really hard for me to believe that rust got to your second stage. Was it really rust? I am sure you saw something or you wouldn't be concerned. If the filter in your first stage is gone and you really got rust to the second stage, both of your regulators need to be taken apart and cleaned. Probably overhauled. If you had that much rust in the tank, it must be tumbled and cleaned before you use it again. PM me if you have any further questions.